Influence of different follicular fractions on in vitro maturation of immature bovine oocytes

Abstract

Three experiments were carried out to investigate whether cumulus cells, Bovine Follicular Fluid (BFF) and granulosa cells, when added as supplements to the maturation medium, support the in virto maturation of immature bovine oocytes. In the first experiment, the maturation medium was supplemented with three different concentrations of the BF F (10, 20 and 50 p.100, respectively). In the second experiment, the effect of three different concentrations of the granulosa (1,10 y 100x 106 cells/ml, respectively), on in vitro oocyte maturation porcentages were evaluated. In the third experiment, the effect of the presence or absence of cumulus cells on the in vitro oocyte maturation rates was compared. Maturation rates at the metaphase II stage, following supplementation with 20 p.100 BFF (60 p.100) were significantly higher (p"O.05) than those obtained in control group (45 p.100). Significant differences between the 10 p.100 BFF, 20 p.100 BFF and 50 p.100 BFF treatments, were not observed. ml and the control treatments (90 p.100 and 85 p.100, respectively) were significantly higher (pa0.001) than when 10 and 10000" cells/ml (66 p.100 and 47 p.100, respectively) were added. Significant differences in the presence (78 p.100) or absence (62 p.100) of cumulus cells (p<0_05) on in vitrooocyte maturation rates were found. The present results indicatethat the presence of cumul us cells surrounding i m matu re oocytes, the addition of low granulosa cells concentrations and BFF added to the maturation medium may be required to induce both nuclear and cytoplasmic maturation of immature bovine oocytes in vitro.

Se llevaron a cabo tres experimentos con el objetivo de investigar si las células del cúmulo, fluido folicular bovino (FFB) y las células de la granulosa, cuando son añadidos como suplemento al medio de maduración, soportan la maduración in vitro de ovocitos inmaduros de bovino. En el primer experimento, el medio de maduración fue suplementado con tres diferentes concentraciones de F F B (10, 20 y 50 p.100, respectivamente). En el segundo experimento, se evaluó el efecto de tres concentraciones diferentes de células de lagranulosa (1, 10 y 100x106 células/ml, respectivamente), sobre los porcentajes de maduración ovocitaria in vitro. En el tercer experimento, se comparó el efecto de la presencia o ausencia de células del cúmulo sobre los índices de maduración oocitaria in vitro. Los índices de maduración en el estadio de metafase 11, siguientes a la suplementación con un 20 p.100 FFB (60 p.100) fueron significativamente superiores